The riverine rabbit, looks even more desperate than has commonly been feared. The conservation status of this Karoo rabbit has, according to the latest IUCN 2002 Red Data List for Endangered Species, been raised from endangered to critically endangered.

There is much jubilation in conservation circles as the waning riverine rabbit population has been given a boost by sightings of this mammal in the Touwsriver District. This is quite remarkable as this is several hundred kilometres away from its known distribution.

This information is from 2003, I was just wondering if anyone had more up to date information.

Not only the most endangered mammal in southern Africa, but also soon top 10 in the world (currently at 11th spot).

Approx. 200 individuals left. Lives in a highly fragmented habitat with lots of fences (impossible for the rabbits to get through) and farmer dogs. Reproduces very slowly, although 1 offspring per year (a figure sometime mentioned in the litterature) is exaggerating low.

Consequently, there is no hope of lowering the RR's Red List status in the comming decades. A (meta-)population experiencing such a intensive bottle neck as the case is here will not recover in the nearest future, regardless of the efforts put in. And because these fur balls a considerable smaller than elephants they can not expect too much support from us humans...

I was under the impression that those found in the Touwsriver district would help to lift them form being critically endangered to endangered. This is why I asked for more info, the info I had was from 2003.

If I'm not mistaken, the Touwsriver population is being examined (genetically) in order to establish whether or not it is a "new" population or a part of the already known populations. It is apparently easy to catch a Riverine rabbit, finding it is the tricky part, which probably explains why this survey is taken some time.

The process of red listing a species (or subspecies) is quit complicated. In order to evaluate the status of a species, and if necessery red listing it, one needs to take a number of factors into consideration. The share abundance/population size is not enough. For example, the number of populations and/or subpopulations, the connectivity (=gene flow) between populations, the effective population size (usually depends to a high degree on [social] behavour among the individuals of that species), the reproduction rate, the variance in the reproduction rate, the threat by human impact, the threat by natural impact (flooding, drought etc) and so on, are all important when trying determine the extinction threat to a species (and accordingly given it its red list status).

The addition of the Touwsriver population will most likely not change anything (regardless of the result from the genetical survey) when it comes to considering the Riverine rabbit as CR. If I remember correctly the population size was estimated to 550 individuals when the rabbit went from EN to CR, and today they are probably far less...

This interesting little creature is very rare, in fact it only occurs in the central parts of the Karoo and lives along dry river courses. We were lucky enough to see one of these rabbits, with extremely long ears, on a recent trip to the Karoo National Park. We saw it near the Bulkraal day visitors area in the early hours of the morning running into a burrow in a dry riverbed . Unfortunately I have no pictures as the rabbit moved very quickly to the safety of its burrow.

while considered the rarest mammal in SA i think that the population size is grossly underestimated as most of their habitat occurs on privately owned land - with farmers thinking that its just another rabbit on their farm and not reporting it. Im sure there is a healthy population on the land that we spotted the one above on, but until now it was undocumented and would have continued to be if zoologists hadn't happened to see them. Im also sure that there are many farms in the area where this is happening....

SAHGCA-UCT wrote:while considered the rarest mammal in SA i think that the population size is grossly underestimated as most of their habitat occurs on privately owned land - with farmers thinking that its just another rabbit on their farm and not reporting it. Im sure there is a healthy population on the land that we spotted the one above on, but until now it was undocumented and would have continued to be if zoologists hadn't happened to see them. Im also sure that there are many farms in the area where this is happening....

I know that, among others, Kai Collins is doing lot of research on the bunny, and informing farmers to report sightings. Hence, I wouldn't say that the population size is under estimated "grossly". However, the rabbit is rather elusive, so sightings are scarce and I dont know if a DNA-census has been undertaken yet (testing the DNA is a more advanced way of the capture-recapture method).